Chair back



FIG. 1 is a front view of the chair back;

FIG. 2 is a side view looking in the direction of the arrow 2 of FIG. 1 of the chair back;

FIG. 3 is a back view looking in the direction of the arrow 3 in FIG. 2 of the chair back;

FIG. 4 is a top view looking in the direction of the arrow 4 of FIG. 3 of the chair back;

FIG. 5 is a bottom view looking in the direction of the arrow 5 of FIG. 3 of the chair back; and

FIG. 6, which appears on sheet 1 of the drawings, is a longitudinal sectional view taken along the line 6--6 of FIG. 1. 

The ornamental design for a chair back, as shown and described. 